We consider the behavior of immiscible and incompressible two-phase ows in a porous medium made of several rock types. Each rock type, is deened by one porosity, one absolute rock permeability ten-sor, two relative permeability curves and one capillary pressure curve. Using two-scale convergence, we get an homogenized model which governs the global behavior of the ow. In this model, macroscopic...

Automatic tools for analyzing student online discussions are highly desirable for better assistance and scaffolding. This paper presents an approach for automatically identifying student discussions with unresolved issues or unanswered questions. We apply a two-phase classification algorithm. First, we classify “speech acts” of individual messages to identify the roles that the messages play, s...

The aim of the present study was to investigate the relations between psychological and physical workload and musculoskeletal neck, shoulder and upper back symptoms. In this longitudinal two-phase cohort study a survey was conducted among non-managerial female elderly-care workers (n = 553). The analyses were based on respondents who were considered free from the respective symptoms at initial ...

This paper presents modelling of non-invasive Ultrasonic Tomography via transmission-mode method for imaging liquid and gas flow. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. The concept of observation time and the imaging technique for twophase flow using fan-shaped beam scanning geometry were presented.

We investigate a reaction–diffusion process in a two-phase medium with microscopic length scale ε. The diffusion coefficients in the two phases are highly different (d1/D = ε2) and the reaction constant k is large. First, the homogenisation limit ε → 0 is taken, which leads to a two-scale model. Afterwards, we pass to the fast-reaction limit k →∞ and obtain a two-scale reaction-diffusion system...

wdm networks offer a technology that can transferred several optical signals into a single optical fiber. This allows for more efficient use of the huge capacity of optical fibers but it also poses new network design and management problems such as routing and wavelength planning. This paper discusses the rwa problem, i.e., the routing and wavelength assignment problem in wdm networks. Given a ...

This paper investigates a different foundation for decision theory in which successive model refinement is central. The idea is to modify utility so that it can sometimes be calculated for an outcome without considering all the relevant properties that can be proved of the outcome, and without considering the utilities of its children. We build partially ordered heuristic utility functions. We ...